# 22
CLEAR
SKIES
AHEAD
CHANGING THE WEATHER AND
FIGHTING MALARIA: WHAT
THE FUTURE OF LASERS HAS
IN STORE FOR US
22
May 2016
PUBLISHER TRUMPF GmbH + Co. KG,
Johann-Maus-Strasse 2, 71254 Ditzingen / Germany; www.trumpf.com RESPONSIBLE FOR THE CONTENT Dr.-Ing. E. h. Peter Leibinger
EDITOR-IN-CHIEF Athanassios Kaliudis,
Phone +49 7156 303 –31559, [email protected]
DISTRIBUTION Phone +49 7156 303 – 31559, [email protected],
www.trumpf-laser.com/laser-community
EDITED BY pr+co GmbH, Stuttgart / Germany; Martin Reinhardt, Florian Burkhardt
CONTRIBUTORS Florian Burkhardt, Norbert Hiller, Tina Hofmann,
Athanassios Kaliudis, Martin Reinhardt, Julian Stutz, Anton Tsuji
PHOTOGRAPHY DanD photography+Video, Erik Jacobs, Angelika Grossmann, Simon Koy
DESIGN AND PRODUCTION pr+co GmbH, Stuttgart / Germany;
Gernot Walter, Markus Weißenhorn, Martin Reinhardt
TRANSLATION Burton van Iersel & Whitney GmbH, Munich / Germany REPRODUCTION Reprotechnik Herzog GmbH, Stuttgart / Germany
Cover picture: Masterfile Royalty Free
PRINTED BY frechdruck GmbH, Stuttgart / Germany
EDITORIAL
This issue features a range of laser applications that are at the more unusual end of the spectrum.
These examples are meant to inspire and provide food for thought, not to mention entertain!
As you’ll discover, these unusual applications are often found in niche segments—and sometimes
they’re surprisingly off the wall! Although laser cutting has evolved into a standard process that
has inevitably lost a little of its fascinating appeal, it’s also a major money-maker. And this
business demands both aspects: standard applications in widespread use and captivating, exotic
niche applications.
The fact is that novelties emerge from niche environments, so some form of crosssubsidization from mass-market applications to niche products makes sense. Exotic niche
applications can also help broaden people’s horizons by enabling them to see and experience
what will be possible in five or ten years’ time. And these attention-grabbing applications
offer a level of fascination that motivates and inspires.
Fascinate, motivate
HOW DO YOU LIKE
THE LATEST ISSUE OF
LASER COMMUNITY?
LET US KNOW:
LASER-COMMUNITY@
TRUMPF-LASER.COM
It’s tough to find the right balance between niche and mass market. We need to try out new
things without overstretching our own capabilities. And that means it’s equally important to
put a halt to development work if it becomes clear that it will never lead to lucrative products.
I personally feel this is one of the most difficult issues of all. Project-based research with multiple
partners in institutional settings plays a key role in this context. In the past, our industry has
always managed to pursue this approach profitably—and we intend to continue in the same
vein in the future. That is why we’ll be meeting with old and new partners at the CODE_n
innovation festival from September 20 to 22, 2016. We’ll be sharing experiences, developing
ideas and hopefully giving new impetus to the future development of photonics.
Lasers and their applications are science through and through, but they also create
an emotional connection. I very much hope that we can stir up some emotion among our readers,
too—and, as always, we’re grateful for any feedback on whether we’ve hit the mark!
peter leibinger, d.eng. h.c.
Vice-Chairman of the Managing Board Head of the Laser Technology / Electronics Division
Cira Moro
[email protected]
3
#22
8 ahead
6 power
10
I SSU E weather research
COMMUNITY
power:
People vs mosquitoes
PAGE 6
glory:
Hello, Mr President
PAGE 7
ahead:
Third generation
PAGE 8
find out more:
The latest research
PAGE 23
4
TECHNOLOGY
And now it’s time
for the weather
By firing lasers at clouds, physicists are hoping to better
understand the weather — and change it. PAGE 10
Wanted: baby !
Using lasers to improve artificial insemination
success rates. PAGE 22
Fotolia / yongkiet, Fotolia / Kolazig, DanD photography+Video, Simon Koy, Gernot Walter
7 glory
18
22
family planning
26
photon ag
24
laservorm
30
popular culture
22/ 2016
eric mazur
OPINION
Erik Jacobs, Laservorm GmbH, Gernot Walter, Angelika Grossmann
“The
most interesting
discoveries in my lab
were all serendipitous.”
Harvard physics professor Eric Mazur reflects on the discovery
of black silicon and the art of courting serendipity.
PAGE 18
James Bond and laser
material processing
How the 1965 movie “Goldfinger” heralded future innovations.
PAGE 30
APPLICATION
Red e-volution
BYD uses laser technology to weld their
batteries for electric buses. PAGE 16
A
cracking job
Laservorm GmbH helps the pharmaceutical industry
get inside chicken eggs without introducing bacteria. PAGE 24
R
AILWAY
Photon AG is building trains with methods previously
only used for cars. PAGE 26
5
COMMUNITY
Mankind’s greatest enemy is tiny, brown, and very hard to catch. But
now researchers have developed a new weapon which they hope will
finally give them the edge they need to defeat the aggressors.
It’s a battle which has been raging for centuries—an army of
blood-sucking creatures just six millimeters long on the attack
against enormous opponents. The aggressors are fast and agile,
and their opponents’ blows often fail to connect. A single bite from
this insect can be lethal, and some 600,000 people die every year
as a result. The enemy is the malaria-carrying Anopheles mosquito,
and the tropical disease it transmits is often fatal, especially in the
developing countries of sub-Saharan Africa. Without treatment,
malaria can kill in a matter of days.
The only way to stay safe is to avoid being bitten. But
the only means of achieving this are mosquito nets and
insecticides. Both of these defenses can only be used
indoors, and the aggressors quickly build up resistance
to the chemicals. But hopes have recently been buoyed by
a new development from the US funded by the Bill & Melinda
Gates Foundation: a “photonic fence” which kills mosquitoes by
zapping them with a laser.
When a mosquito flies into an area protected by a photonic
fence—for example a school, hospital or village—cameras
Bzzzz … zap !
on both fence posts detect the intruder’s shadow in the
This female
light between the posts. The system immediately fires a
mosquito didn’t
non-lethal laser beam at the insect and uses the reflected
make it through
light to determine its size and the frequency at which
the laser fence.
its wings are beating. This information tells the system whether the intruder is an Anopheles mosquito
and also identifies the insect’s gender. This is an important distinction to make because only females
bite. Once the mosquito is confirmed as a female
Anopheles, the system fires a second, lethal laser
beam, shredding the insect in mid-flight.
All the components used in the fence come
from inexpensive consumer electronics, a fact
which will hopefully make the fence affordable
in malaria-stricken regions. Who would have
thought that the decisive weapon in the battle
against malaria would turn out to be a laser diode
for a Blu-ray player? 6
Fotolia / yongkiet, Fotolia / kolazig
P
EOPLE VS.
MOSQUITOES
“WE HAVE A STRATEGY!”
DanD photography+Video
Professor
Lin Li from
Manchester is
the President
of the Laser
Institute of
America for the
year 2016.
Professor Lin Li, the elected President of the Laser Institute of America for the year 2016, wants to
whip the Institute into shape, increase its profile in
Asia and attract more members.
After 20 years of high-power laser research,
340 articles in respected scientific journals and 47
patent applications for laser material processing
and photonic science, Professor Lin Li has found
a new challenge. The chair of laser engineering at
The University of Manchester is also the President
of the Laser Institute of America for the year 2016.
Li wants to pursue reform: “We are developing
a long-term vision and strategy for the LIA,” he
says. “We will also review the institute’s finances and come up with a sound financial plan that
will facilitate healthy growth in the community.
This will enable us to better serve our members,
the laser community and society in the future.”
During his term of office, Li aims to expand the
LIA’ s membership list. “To attract more people,
LIA plans to improve its services for members,”
says Li. “We also want to increase the institute’s
international profile.” To achieve these goals, he
plans to target the U.S. job shop sector and also
Asia. “The Asian laser community is expanding
incredibly fast,” he says. “I’m eager to know more
and to learn about what they are looking for.”
Born in Shenyang, China in 1959, Li completed his Bachelor’s degree in control engineering at Dalian University of Technology in 1982,
which laid the foundations for his scientific career. He came to the UK to study laser technology in 1985 and earned his PhD from Imperial
College London in 1989. Li spent six years as a research associate at the University of Liverpool before moving to his adopted home of Manchester.
As Li says, “Manchester is where Ernest Rutherford and Niels Bohr first discovered the structure
of the atom, where Alan Turing invented the first
programmable computer and where the Industrial Revolution started, which changed the world.”
He keeps in touch with his Chinese roots through
his hobbies: playing flute and erhu in a band that
performs Chinese music, and practicing Tai Chi.
Li was elected fellow of the Royal Academy of Engineering and received the prestigious Sir Frank
Whittle Medal in 2013. Contact: [email protected]
7
“STRONGER,
FASTER, AND
SHORTER”
Physicists, doctors, chemists—all are
waiting for shorter and higher-energy
laser pulses. And all want to conduct
research on the tiniest processes in the
universe. Dr. Hanieh Fattahi shows how
it’s done.
You talk about the “third generation
of femtosecond technology”. What does
this mean?
The first generation of femtosecond pulses came from dye lasers, which could
produce different frequencies. But, although they yielded ultra-short pulses, it wasn’t possible to increase either
the pulse energy or the average power—in other words, the repetition rate.
Next came titanium-sapphire-based laser technology. Here you had to choose
whether you wanted to crank up the
pulse energy or the repetition rate. Doing both at the same time doesn’t work
because it causes the crystal to
overheat. With the third generation, it is possible to
create many very
8
How does it work?
The third generation is based on OPCPA—
short for optical parametric chirpedpulse amplification. To really get the
most out of OPCPA, however, you need
one heck of a pump source. It needs to
be scalable and stable. Luckily, one exists in the form of the TRUMPF turn-key
Ytterbium:YAG thin disk laser. This laser
reliably generates pulses with durations
of 900 femtoseconds and is freely scalable in terms of repetition rate and energy. We amplify the pulses from this highpower disk laser and make them 1,000
times shorter with coherent synthesis.
In my dissertation, I show how it is possible to attain the following parameters:
ultra-short pulses with durations of one
field cycle, peak pulse power in the terawatt range, average power in the hundred
Watt range and a repetition rate between
500 and 1,000 Hertz. This wasn’t possible before.
What is the goal of your research?
We want to use these compressed and
amplified laser pulses to generate attosecond pulses that are even shorter. To
do this, we focus the pulses into an inert gas beam and accelerate the electrons of the gas atoms. As the electrons
fall back to their ground state, they emit
an attosecond pulse. So far, the maximum photon energy that we’ve gotten
out of the inert gas atoms is 200 electron volts. However, with the third generation of femtosecond technology, we
will hopefully increase the photon energy to over a thousand electron volts. Kiloelectron volts in the lab—the dream of
every high-energy physicist!
What can you do with shorter
attosecond pulses?
They will allow us to make the movements of electrons in the atoms of solids visible and to actually film them! The
attosecond pulses function as a sort of
camera shutter here. And if this helps
us to better understand the interplay of
light and matter, then one day it will be
Could you explain how you do this?
possible to build optical tranTo do it, you need a very broad color sistors that open and
spectrum. The more frequency compo- close at unbelievable
nents you combine in a pulse, the shorter speeds, enabling suit becomes. However, there are physical per-fast computlimits with OPCPA: you can only am- ing operations.
plify a few frequencies simultaneously.
So, I designed an amplifier setup to get What motivates
around this limitation: I split the laser you personally?
pulse into various frequency components I want to have
and send each one through a separate the opportunity
amplifier. It’s a kind of multi-channel to look inside
OPCPA system, if you like. In this way, an atom one day. I
I obtain various high-energy ultra-short love the idea of peerpulses of different frequencies. Then I ing down that deeply! You
resynchronize them using a waveform know, around 95 percent of the
synthesizer.
day-to-day life of a researcher is pretty
unglamorous stuff: setting up lasers, fixAnd what is the result?
ing defective components. But the othA sub-cycle pulse with a spectral band- er five percent, when everything works
width of several octaves. In this way, and you make progress—those times are
we can compress the duration of laser so wonderful that they make it all worthpulses down to as much as 500 attosec- while. onds. So we actually can obtain attosecond pulses directly from the OPCPA Contact: [email protected]
and the Ytterbium: YAG disk laser!
The laser pulse
amplifier compresses
the pulses by a
thousandfold.
Simon Koy
short pulses with high pulse energy and
also a high repetition rate.
Hanieh Fattahi in
the laboratory. She
splits ultra-short
pulses into color
spectra, which
she amplifies
individually and
recombines into a
single pulse. This
hugely increases
the intensity of the
pulse.
PERSONAL PROFILE: Hanieh Fattahi
studied biophysics at Sharif University
of Technology in Tehran and has been a
researcher at the Laboratory for Attosecond
Physics at the Max Planck Institute of
Quantum Optics in Munich since 2008.
PROJECT PROFILE: The goal of
attosecond physics is to investigate the
fastest and smallest processes in the
universe. Using ultra-short laser pulses,
the physicists generate flashes of light out
of gas atoms in the attosecond range.
An attosecond is a billionth of a billionth
of a second (10 –18 seconds). The researchers
use these flashes to make the movements
of electrons visible inside the atom. They
are working on filming electrons in 3D.
The founding father of attosecond physics
is Prof. Ferenc Krausz, who heads
research at the Max Planck
Institute of Quantum Optics.
9
TECHNOLOGY
Rohan Kelly / action press
Could a laser
save the sunny
weather?
10
And now
it’s time
Turbulence researcher Eberhard Bodenschatz fires lasers at clouds to help
him solve the mystery of why it rains. Meanwhile Jean-Pierre Wolf, an
expert in nonlinear optics, is hoping to use his lasers to make his own weather.
for the
weather
11
12
Gernot Walter
“I want us to finally
get to the bottom of
turbulent mixtures,
and clouds
are the perfect test
environment.”
Max-Planck-Institut für Dynamik und Selbstorganisation
G
ermany’s highest-altitude building is packed to the no bigger than a few micrometers. We’ve been doing that in our wind tunrafters with high-tech equipment. The Schneefern- nel for a while, but this summer we’ll be using our new laser to perform
erhaus was originally set up as a hotel for tourists on the first measurements on real clouds on the Zugspitze,” says Bodenschatz.
the Zugspitze at 2,656 meters above sea level. But in
the 1990s, the last hotel guests left and the scientists Laser flashes To make the motion of the swirling droplets visible,
arrived, transforming the building into an environ- Bodenschatz and his team need plenty of light. “That’s why we need the ulmental research center. Now an ultrashort pulse laser trashort pulse laser. It delivers up to 50,000 flashes a second with 40 millifrom TRUMPF has made its way up the Zugspitze, too. Eberhard Boden- joules per pulse. Those parameters give us enough photons in the measureschatz, professor of experimental physics at the Max Planck Institute for ment zone to make the swirling droplets visible,” Bodenschatz explains. He
Dynamics and Self-Organization in Göttingen, purchased the device for his notes that the laser pulses have very little effect on the droplets themselves:
lab in the Alps: “We’re hoping to use the laser to reveal the dynamics of water “At most they get a little warmer, but that doesn’t affect how they move.”
droplets and ice particles in clouds so we can see exactly what’s going on.”
Bodenschatz is currently developing another experiment designed to investigate droplet distribution in clouds on a larger scale. His idea is to hang
Capturing patches of turbulence on video The laser light ca- a high-speed camera from a long rope and fly it directly into a cloud using
ble runs from the laser through the laboratory ceiling to a flat roof where a balloon-kite hybrid known as a Helikite. “We fan out laser light from bea climatized, waterproof container the size of a beer crate is positioned on low, firing high-intensity, green pulses around 100 meters into the cloud.
a seven-meter-long rail. The crate contains four high-speed cameras. The That makes the turbulence visible—and with the TRUMPF laser we finally
researchers in the lab, and the measuring device on the roof, wait patiently have a beam source that is up to the task.” (# 2)
for the weather to deteriorate—and they start collecting data the moment
a cloud moves across the roof. The optics system expands the laser light to Three unsolved puzzles However fascinating he finds the weatha diameter of five centimeters and the light pulses are projected at a vertical er, Eberhard Bodenschatz really has his sights set on a broader context. He
angle toward the camera box onto the cloud particles. The forward scatter- has devoted virtually his entire career to investigating turbulent fluxes. “We
already have a few equations for this field of physics, but the process is so
ing causes the particles to light up with every
pulse of light, and the cameras record this
complex that the parts we understand are just the tip of the iceberg. And
in the form of stereoscopic images takwhen it comes to inertial (i. e. heavy) particles in turbulence, we don’t have
en at a distance of around 60 centiany equations at all! So, the only solution is to collect data on particles
meters from the lens. In order to
in the turbulence and subject it to statistical analysis. Clouds are percreate a three-dimensional video
fectly suited to studying these complex processes because they ocof the cloud particles, the highcur in nature and consist of just four ingredients: water vapor, ice,
tech crate keeps pace with the
airborne particles known as aerosols, and, of course, air. “My goal
cloud’s average speed as it travels
is to understand how collisions and evaporation occur in turbulent
along the rails (# 1). This enables
mixtures.” Bodenschatz hopes this will allow him to draw concluthe cameras to track individual
cloud particles, snapping about
15,000 images a second. These
images are then instantly converted into 3D pictures by the
computer. It takes just one sec#1
ond to complete the measurements. Then the sled returns to
All these
its starting position and the enexperiments
are
tire process starts over. This is
already
up
and
the method the researchers use
running in the
to film small patches of turbulab. But in recent
lence—each a few cubic cenyears researchers
timeters in size—in order to
have made the
discover what happens to tileap to real
ny cloud particles in that sinweather.
gle second of time. “Each measurement tracks somewhere between 300 and 1,000 individual
MEASURING TURBULENCE
Prof. Eberhard Bodenschatz, Max Planck Institute
for Dynamics and Self-Organization
cloud particles, each of which is
IN CLOUDS
TECHNOLOGY
sions on other mixing processes such as those that take place in ocean currents, technical sprays, and even combustion engines. The combustion process in a diesel engine, for example, mixes together thousands of individual components. “Understanding clouds eventually improves one’s understanding of combustion, too.”
And clouds harbor yet another secret. Rain only falls when numerous
tiny droplets suspended in the air combine to form one large raindrop. This
raises the fundamental question of how large droplets are formed from smaller ones. “And that’s something physics can’t answer at the moment. The droplets are heavier than air and spin off at an angle as they whirl around. We understand the process pretty well on an individual level, but unfortunately we
don’t understand the ‘avenues’ of turbulence, and those are changing all the
time,” says Bodenschatz. “The droplets live in the wildest rollercoaster imaginable. What we’re interested in now is how many collisions take place and
how this causes larger droplets to form which then fall toward the ground,
swallowing up numerous tiny droplets on their way.”
This question of how small particles combine to form larger ones in turbulence is also relevant to the formation of planets. “Look at our current
models and you would be forced to conclude that space shouldn’t contain
any clumps of matter with a diameter larger than about one meter, since
they burst apart when they collide. To have the kind of gravitational pull
required to cluster matter together you would need clumps measuring at
least 100 meters across. “Obviously we know that planets exist. But how is
that even possible? We’re hoping that our experiments on particles in turbulence will give us some clue as to how our world was formed in the first place.”
An improved understanding of clouds will also have some more immediate, practical benefits, such as improving the accuracy of predicting when
and where it will rain or snow. “Wet clouds produce rain up to ten times
sooner than current models predict. And I believe that has something to
do with turbulence.”
For climate researchers, cloud formation is one of the most important
issues of all. A huge community of scientists is currently striving to cre-
#2
ate better climate models—and Bodenschatz’s work forms part of these
efforts, too. “But soon things will develop even further: it won’t be long
before climate change becomes so serious that we’ll be actively intervening in weather processes.”
Stretching things out Jean-Pierre Wolf has already reached pre-
cisely this stage at the University of Geneva. He wants to use laser beams
to influence cloud formation and control lightning. The Swiss expert in
nonlinear optics came up with the idea while investigating how air reacts
when you expose it to a high-power laser beam. His results showed that the
air ionizes. This is due to a phenomenon known as Kerr-induced self-focusing: the field strength of a high-intensity laser beam affects the refractive index of the air in such a way that the air itself acts as a kind of focusing lens for the laser beam. This creates high intensities that ionize the air.
Electrons are released, defocusing the laser beam and causing the entire
process to start over. The beam remains stable, continuously focusing itself.
“With the right beam source, we can stretch the focus out to a length of one
hundred meters,” says Wolf. “Ionization produces plasma channels known
as filaments—and that’s what we can use to affect the weather.”
Using lasers to trigger lightning from clouds Wolf is currently
working on three applications for his filaments, the first of which is to trigger
lightning in clouds. “The filaments trigger discharges and the lightning follows the channel. So, in addition to triggering lightning, we can also cause it
to discharge in a certain direction,” says Wolf. This gives Wolf two possible
ways of eliminating the risks posed by thunderclouds. He can either trigger
lightning within a cloud that never actually reaches the ground—discharging the cloud until it becomes calmer (# 3)—or he can use the filament to
guide the lightning to a standard lightning conductor on the ground (# 3a).
“There is huge demand for improved protection. The costs associated with
thunderstorms and lightning strikes run to five billion dollars a year in the
US alone, primarily due to disrupted air traffic and damage to aircraft and
USING LASERS
#3
FOR CLOUD
MEASUREMENTS
AND WEATHER
#3a
MAKING DROPLET
DISTRIBUTION VISIBLE
MANIPULATION
DISCHARGING
STORM CLOUDS
13
TECHNOLOGY
“If we use lasers in
the right way, we
could eliminate the
damage caused
by lightning strikes
in the future.”
Drilling holes in clouds Wolf also hopes to use his
filaments to improve communication between satellites
and ground stations, which is often obstructed by clouds
and fog. In the course of his experiments, Wolf hit upon a
further phenomenon of ionization. The jump in temperature of the air molecules triggers a shock that produces a
sudden sound wave. “We can use this acoustic explosion
to push aside droplets in mist and clouds, basically using
the long laser focus to drill a channel through the clouds.”
This requires the individual shocks to take place at very
short intervals. “And that’s why this application is all about
having a very high repetition rate”. The hole in the clouds
could be used to transfer information between the Earth and
space without anything getting in the way—and the data transfer could also take place via laser !
Prof. Jean-Pierre Wolf, University of Geneva
Delaying rainfall The laser-generated
filaments can also be used to affect the weather in other ways. Wolf converts vapor into
small water droplets that hover in the air—
in other words, he creates clouds. For water
vapor to condense in the air, you need surfaces on which the phase transition can take place,
in this case aerosols such as dust or sand. “Ionization with the high-power laser enables us to make
the existing aerosols more hydrophilic. They attract more
moisture, forming droplets where there were none before,” says Wolf (# 4).
“What we can’t do is make the cloud rain. Once we’ve created it, it simply
lives out its natural lifespan.” Where Wolf has succeeded, however, is in preventing wet clouds from raining for a certain period of time under labo-
#4
MAKING CLOUDS
14
ratory conditions. To do this, he draws on the principle
investigated by Eberhard Bodenschatz, which states that
small droplets do not fall. By turning the aerosols contained in the cloud into genuine moisture magnets, Wolf
ensures that the water spreads itself over multiple surfaces.
“The droplets split up and are not big enough to fall to
the ground. In the future, this could enable us to prevent
wet clouds from raining until they are over dry areas.
This could help us combat both droughts and flooding,”
Wolf explains, setting out his vision of how the technology could be used. (# 5)
Contact:
Prof. Eberhard Bodenschatz, [email protected],
Prof. Jean-Pierre Wolf, [email protected]
#5
DELAYING RAINFALL
Prof. Jean-Pierre Wolf, Gernot Walter
power lines.” Wolf would like to see stationary laser systems installed around airports
and power plants, which could discharge approaching storm clouds before they pose any
danger. “I think we’ll be ready to do that in five
years’ time. It works perfectly under laboratory conditions and we’ve already run successful tests outdoors, too.” The key to success is
choosing the right beam source. “You need a
femtosecond laser with a peak pulse power of
one terawatt and a high, stable repetition rate of
more than one kilohertz. TRUMPF Scientific
Lasers is currently developing a laser for me
with those specifications.” The collaboration
stems from some trial measurements for lightning conduction carried out at the TRUMPF
laboratory in Munich.
laser-community.com
www.laser-community.com/en/6297
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Laser Metal Deposition for additive
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Read more on your smartphone,
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also browse all of our previous
articles and recommend them to
friends and colleagues.
15
red e-volution
More and more cities around the globe are opting for electric buses made by BYD.
One of the strengths of this Chinese company is its in-house expertise in high-performance
batteries. Laser technology is used to weld their highly sensitive components.
It looks like any of the other thousands of red double-decker
buses plowing through the loud traffic on London’s streets,
but if you listen closely you’ll soon realize that this number-16
bus is different. Instead of the usual engine rumbling, all you
can hear is a high-pitched hum. Indeed, it is the world’s first
double-decker bus designed to run on electricity. It is part of
a plan to improve air quality in the English capital. More and
more cities around the globe share London’s dream of zeroemissions local transportation and are switching to environment-friendly electric buses.
THE FUTURE PROMISE OF ELECTROMOBILITY The
Chinese company BYD has taken advantage of this trend and is
driving it forward. The three letters making up the company’s
name are indicative of its great ambitions—they stand for
“Build your dreams.” In 2015, BYD sold 7,500 electric buses
to cities around the globe—more than any other manufacturer. No less than 160 municipalities in 40 countries
have run trials of the different variants of BYD’s electric
bus, including New York, Tel Aviv, Montevideo, Kuala
Lumpur and now London. Electromobility is the way
16
forward to a greener future. Electric motors do not produce
harmful CO₂ emissions and are much more efficient than internal combustion engines: a gasoline-powered vehicle converts only 19 percent of the energy it consumes into motion,
whereas electric vehicles have a conversion efficiency of
64 percent.
MADE IN ASIA Thousands of kilometers away, in the
southeast Chinese city of Huizhou, Liu Huaping, BYD’s process department manager shows visitors around the plant
where BYD manufactures the batteries for its electric buses—
one of three such sites. “The batteries are the core components of our vehicles; they determine how far the buses can
travel. They have to be able to store as much energy as possible
without being too bulky or heavy,” says Huaping.
When designing electric vehicles, the
biggest challenge is the storage battery, not the engine.
One of the reasons for
BYD’s unparalleled success as a manufacturer
In October 2015
the world´s
first electric
doubledecker bus
entered service
in the streets of
London.
APPLICATION
BYD, Gernot Walter
BYD developed
its own iron
phosphate battery
for electric buses.
They are safer than
the more common
lithium-ion
batteries.
of electric buses is that the company was able to build on
its reputation in the battery industry. BYD began producing
rechargeable batteries in 1995, but didn’t turn its full attention
to the automotive industry until 2003. Almost every single
component is manufactured by BYD in house: from the electric
motor to the steering wheel and the fenders. The company
grew rapidly and soon joined the ranks of China’s largest carmakers. Buses were finally added to its portfolio in 2009. BYD
developed its own iron phosphate battery for these vehicles.
Iron phosphate batteries are safer than the more common
lithium-ion batteries because they are not susceptible to the
thermal runaway phenomenon, which can cause the latter
to catch fire or explode. The batteries developed by BYD are
also kinder to the environment because they are
recyclable and don’t contain any heavy metals. Efficient and reliable production processes are the key
to meeting the growing demand for these energystorage devices, while ensuring quick delivery and
affordable prices. “Welding plays a significant role
in the battery manufacturing process. Among other
things, it is used to attach the connectors and to seal
the battery enclosure,” explains Huaoping.
BYD uses different techniques depending on
their suitability for a particular type of welding job.
They include resistance welding, ultrasonic welding and electron-beam welding. “But laser welding
is our method of choice for applications requiring a high degree of precision,” says Huaping.
A glance at the factory’s fleet of machines shows how important lasers are in the company’s manufacturing processes. BYD has installed a total of 120 TRUMPF laser
machines in its battery plant: 70 from the TruDisk se-
ries and 50 from the TruPulse series. Huaping illustrates this
point by fanning out three thin strips of metal: “The majority
of our welding operations involve part thicknesses of no more
than two millimeters or even less. These parts are made of copper, aluminum or an aluminum alloy.” So as not to damage the
sensitive battery components, the welding process must have
the least possible impact on the surrounding material. “Fine
weld seams, low heat diffusion, low intrinsic stress and minimal distortion are our key requirements for such processes,”
says Huaping as he walks toward a TruDisk laser machine.
Disk lasers are ideally suited for welding highly reflective
materials such as copper or aluminum. The connections between each battery cell and the next are welded this way. “By
adjusting the focus of the laser beam, we can rapidly move
from one weld point to the next. We can also adapt the working angle to avoid damage to the optics,” explains Huaping,
who is meanwhile walking toward a TruPulse system. “We use
pulsed lasers to seal our battery enclosures because the weld
seams have to be absolutely gastight. This process must not
generate too much heat because this could damage the internal components of the battery.” The chosen method fits the
bill because it allows time for the material to cool down between successive laser pulses.
250 KILOMETERS Meanwhile back in London, it’s time
for our number-16 double-decker bus to return to the depot
and recharge its batteries after 250 kilometers on the road. A
fully charged battery can easily cover this distance, and the
bus will be ready to go again after it has been plugged in
for four hours. It won’t be the last electric bus operating
in the city: London Transport plans to integrate 300
electric buses into its fleet by 2020. 17
18
OPINION
,
n
e
t
s
i
l
,
d
i
a
“I s
e
v
a
h
y
l
l
a
e
r
we
o
t
n
i
k
o
o
to l
s
r
o
t
c
u
d
n
o
c
i
sem
”
!
w
no
Erik Jacobs
Harvard physics professor
Eric Mazur reflects on the discovery of
black silicon and the art of serendipity.
19
Y
You originally wanted to be an
in ordinary materials. In our new
material, photons essentially behave
artist, but now you’re a professor
like electrons, giving us a far simpler
of physics. What went wrong?
I don’t think those two things are as and more efficient way of manipufar apart as they might seem! Scien- lating, bending and squeezing light
tists need to be creative, they need at the nanoscale. That’s one of the
the ability to recognize and articu- projects we are working with at the
late patterns, just like artists. The act moment. The overarching idea is to
of interpreting a series of measure- fabricate an optical chip that could
ments has certain similarities to a process optical signals. Before we
painter steadily building up a scene. manufactured this zero-index maTake Leonardo da Vinci, for exam- terial, we demonstrated that light,
ple: he was a great artist and a great including ultrashort laser pulses,
scientist. Personally, I was inspired can be guided by “nanowires,” pavto pursue both of these areas by my ing the way for nanophotonics in a
family. My father was a professor of broad frequency range. We are altheoretical physics and my grand- so expanding our research in the
father was an engineer. When I was realm of biophotonics. For examlittle, they were always giving me ple, we developed an efficient way
science books and engineering kits. of using light to punch small holes
My mother was an art historian who in cell membranes that we can use to
taught me a lot about visual arts and insert genetic material into the cell.
graphic design. As a teenager, I re- And with an ultra-short pulsed laser,
ally wanted to become a photogra- it only takes a second for us to perfopher or filmmaker. But in the end I rate tens of thousands of living cells,
chose science because it had always potentially revolutionizing medicine
been my strongest subject at school. and medical research.
To be honest, the main reason was
that I thought it would be easier to You’ve already worked in so
make a career in science than in the many different areas of optical
arts. But I still have my artistic side. research. How do you keep
I love photography and I invest great making all these discoveries?
effort into crafting the perfect de- I’ll tell you something: the most insigns for the slides I use in my talks. teresting discoveries in my laboratory were all serendipitous. None of
What are you working
these discoveries resulted from careful planning. Although …, at a Chion at the moment?
So many different things. To give nese restaurant I recently got one
you one example, our group is cur- of those fortune cookies when the
rently investigating how light be- check came, and it said: “Good luck
haves when you send it through is the result of good planning,” and
a material with a refractive index that actually got me thinking. Perof zero. We’ve built what we call a haps what really matters is giving
metamaterial, a gold-clad transpar- luck a chance to run its course. Peoent photoresist in which tiny crystal- ple generally see research as someline silicon pillars are embedded. It thing focused and linear, but trying
turns out that light behaves very dif- things out and playing around are
ferently in this material than it does perhaps just as crucial. I’ve always
20
encouraged trying out new things
and pushing boundaries in my research group.
st
“The mo
ng
interesti n
ie s i
r
e
v
o
c
s
i
d
ratory
o
b
a
l
y
m
were all
tous.“
i
p
i
d
n
e
r
se
Could you give an example?
In 1997 my research group and I discovered black silicon, a form of silicon that is extremely good at absorbing light and is now finding applications in sensors and solar cells.
At the time we were using femtosecond lasers to investigate how
carbon monoxide reacts on platinum surfaces to form carbon dioxide, a reation that occurs in the
catalytic converter of a car. This research was funded by the U.S. government for two successive threeyear periods, and when I submitted
my third application for a new round
of funding, I felt that I had better offer something else too — otherwise
they might stop playing ball. So in
my application I wrote, “We will also investigate other materials such as
semiconductors.” This got a program
manager excited enough to give me
a call and ask for more details. As I
had no specific ideas, I quickly made
something up. The funding was extended for another three years and,
as you might imagine, we continued our work on platinum. As the
end of that third funding period approached, however, I suddenly got
nervous because I had promised research on semiconductors. I called
one of my students in the lab and
said, “Listen, we really have to look
into semiconductors now!” We unearthed some silicon wafers in the
corner of the lab and my student
found a cylinder of sulfur hexafluoride from our gas store as a reaction medium. He then fired femtosecond laser pulses at the surface of
the silicon and it turned completely black, darker than black velvet.
LIFE Eric Mazur was born in Amsterdam in 1954.
He studied at Leiden University and moved to Harvard
University in 1981 where he was tutored by the Nobel
laureate in Physics Nicolaas Bloembergen.
LASERS Mazur pioneered the use of ultra-short
pulse lasers as a research tool. In 1989 he built a
femtosecond laser at Harvard and became the first
person to systematically investigate the effects of
femtosecond laser pulses on materials. His research
has led to numerous applications in both medicine
and industry.
CAREER Eric Mazur heads up the Mazur Group at
Harvard which employs around 40 people. The team
conducts research into areas including femtosecond
laser microfabrication and nanosurgery,
nonlinear nanophotonics, and pedagogical
techniques in the realm of science.
Erik Jacobs
Black silicon was born. He called me,
I came over and we examined the
surface. That haphazard discovery
ultimately led to a whole new field
of research, a new company, and
novel products.
But eventually something must
have sparked your interest?
In my third year, when I was just
about ready to quit, I joined a research group and started to work in
the laboratory. My project involved
laser spectroscopy of cold gases, and
I was really excited to be in the laboratory and have a chance to observe phenomena that nobody had
ever seen before — uncovering new
knowledge. Suddenly I was hooked.
about first spending a year in the US a bit unusual for a top researcher?
as a postdoc and learn more about I love it! I think it’s so important
optics?” I thought it was a great idea to get people interested in science,
and Philips agreed to keep my job and I think one way to do that is by
open for me. I wrote to Harvard and changing the way we teach. I’ve althey accepted me as a postdoc. And ready told you how boring I found
what can I say? It’s been a long year, most lectures when I was a student.
When I started teaching, I realized I
because I’m still at Harvard.
was doing exactly the same thing as
What made you change your mind?
my teachers had done to me. I may
I suddenly found myself in a place have been a good lecturer, but I was
where 17-year-old string theory en- a terrible teacher. My students memthusiasts were chatting to 70-year- orized facts and regurgitated them
old Sanskrit experts. Politicians, on the exam—much like I had done.
writers and artists were visiting the This process bears no relation to
campus giving talks. And when I knowledge discovery. So I developed
thought about Philips all I saw was a new active learning approach, now
that long, long corridor with an end- called the “flipped classroom”: stuless row of PhD nameplates stretch- dents prepare before coming to class
ing along the walls. All the offices and the class period is more like a dewere occupied by male physicists bate. I teach by asking questions. My
aged between 27 and 40 who spent students are constantly involved, and
all day long solving predefined prob- they learn more. My goal is to create
lems. Suddenly it seemed so claus- “aha!” moments in the classroom.
trophobic. So I became an academ- When I see that look of sudden unic after all. As you can tell, I make a derstanding on a student’s face, I
feel a great sense of satisfaction. habit of changing my mind.
You’ve followed quite a
linear career path …
Not at all. I’ve zigzagged all over the
place. When I was five years old, my
grandfather gave me a book about
the universe. I immediately knew
that I would become an astronomer. And that made you want
So when I was 17 I began a degree to be a professor?
in astronomy at Leiden University No! I was determined to follow a cain the Netherlands. But after just six reer path that was different from that
weeks I was totally disillusioned. In- of my parents, I didn’t want to bestead of investigating the big ques- come an academic. So when I fintions, all we were doing was working ished my doctoral thesis, I applied
on formulae for calculating star po- to Philips and was offered a job in
sitions. I wanted to see the forest, but their research laboratories. That was
all they kept showing me were the in 1981 when Philips was working on
individual trees. I switched to phys- the development of the CD in a joint
ics, but as I quickly discovered, phys- venture with Sony. I was assigned to
ics wasn’t any better than astronomy. a group that had to reduce the diamClasses were really dull and mostly eter of the discs from 30 centimeters
focused on endless problem-solving. to the 12-centimeter size we’re familI stuck with it because I was too em- iar with today. When I told my father You teach introductory courses for
about the job offer he said, “How non-physicists. Isn’t that
barrassed to switch fields again.
Contact: Eric Mazur, [email protected]
21
TECHNOLOGY
(Fig. a)
On a mission
to conceive
For some couples, artificial insemination is the only way to have children
of their own. Researchers are constantly improving the methods used in
reproductive technology—and lasers are providing assistance in key areas.
Sperm must display a certain amount of agility for artificial insemination to work. DNA-strand breaks in sperm
cells have a negative effect on factors such as sperm motility, representing a possible cause of miscarriages. For
many years, doctors assessed quality by examining sperm through a microscope—a relatively imprecise method.
Lasers give greater certainty to the process. Two highly focused beams act as “optical tweezers” that are used to hold
the spermatozoa firmly in place. The way in which the laser light is reflected provides important information on
the sperms’ motility (Fig. a), enabling doctors to identify the best candidates. The optical
tweezers also provide support in the actual process of insemination, transporting the spermatozoa to the egg. Further assistance is provided by a UV laser
beam, which drills a tiny hole in the egg to help the spermatozoa get
inside (Fig. b). The ability to influence the process with such precision makes this a highly reliable method of insemination—and the
non-contact nature of the technology eliminates any possibility
of contamination.
Pregnancy begins once the egg has been implanted in the
uterus. For this to take place, the embryo must “hatch” from
the egg, something that sometimes fails to occur because
the egg membrane (zona pellucida) is too tough. A method
known as “assisted hatching” can help the embryo penetrate the zona pellucida. This is performed
using an infrared laser, which perforates the membrane (Fig. c).
Mother Nature is left to
take care of the rest. HOW DO OPTICAL
TWEEZERS WORK ?
When a photon collides
with a particle, the force
of the impact causes two
things to happen: the
photon changes course,
and the object struck is
set in motion. If the light
is powerful enough, it can
push the object away
with significant force. This
effect can be harnessed
by using two beams to
hold or move the object
in the same way you would
use a pair of tweezers.
(Fig. b)
Gernot Walter
(Fig. c)
22
LASER WELDING OF CARBON STEEL TO STAINLESS STEEL 316L The petrochemical and oil industries primarily use welding to join different metals and alloys due to the advantages
this method offers. In his doctoral thesis for Loughborough University (UK), Mohammadreza Nekouie Esfahani (31)
set himself the goal of investigating the fundamental phenomena that occur inside the dissimilar weld zone between
carbon steel and stainless steel 316L and their effect on weld quality.
The results of his work are available at: bit.ly/1MVtyoK
SIMULATION OF LASER ADDITIVE MANUFACTURING AND ITS APPLICATIONS For his dissertation at The Ohio State University, Yousub Lee (36) investigated heat transfer, molten metal flow
and free surface evolution in both powder injection and powder bed forms of metal additive manufacturing processes.
The results provide an in-depth understanding of the underlying mechanisms of solidification morphology,
solidification scale and surface finish quality.
The full dissertation is available at : bit.ly/1NWnc92
further reading
So what are the next steps for light as a tool ? The work of five young
researchers gives some idea of what possibilities are feasible.
LASER WELDING OF BORON STEELS FOR LIGHTWEIGHT APPLICATIONS
Boron steel is strong and light, making it a good choice for lightweight design. For his thesis at University West
in Trollhättan, Sweden, Karl Fahlström (29) investigated the suitability of this material for laser welding.
His work focused on the occurrence of cracks, porosity and strength-reducing microstructures that can occur
during laser welding, as well as distortion studies. The results provide insights into boron steel laser welding
and give some ideas on how to avoid problems with this application in production environments.
To request a copy of the full thesis, please send an email to: [email protected]
P-DOPED (AL)GAN LAYERS BY MOLECULAR BEAM EPITAXY
For his thesis at the Swiss Federal Institute of Technology in Lausanne, Marco Malinverni (27) grew p-doped aluminum
gallium nitride layers using molecular beam epitaxy—a process that enables scientists to grow thin crystalline layers by
means of physical vapor deposition. Malinverni succeeded in using this method to realize electrically injected indium
gallium nitride-based laser diodes with a lasing wavelength greater than 500 nanometers. These green laser diodes
are an important tool for producing extremely compact and energy-efficient RGB projection systems. You can
read the full thesis here: bit.ly/1RM2psL
Private
LASER-DRIVEN PROTON ACCELERATION WITH TWO ULTRASHORT LASER PULSES
Laser particle acceleration could reduce the cost of cancer therapy—if the proton energies are high enough. This is
why Jürgen Böker (34) decided to search for unknown acceleration mechanisms as part of his thesis at the Heinrich Heine
University in Düsseldorf. He focused two laser pulses with peak powers of a few hundred terawatts on a thin foil in
a vacuum. The ions were accelerated to mega-electron-volt energies through the interaction between the plasma and
the laser pulse, showing signs of a new acceleration mechanism.
The full thesis is available at: bit.ly/1MDti2k
23
APPLICATION
The beam of a CO2
laser is divided,
allowing it to cut
four eggshells at
the same time.
A cracking job!
The pharmaceutical industry wants to know: How do you remove the shell from a chicken egg
without damaging the egg inside ? Laservorm has the answer: with a laser !
“An egg is perfect,” says Thomas Kimme, managing director of the laser systems manufacturer Laservorm GmbH. “From the moment it emerges, it’s
a sealed space that keeps nutrients inside and keeps bacteria out.” Kimme
grabs a pencil and draws two rings on a piece of paper, one just barely inside
the other. “This perfect space has a double layer of protection.” The outer
calcareous shell, which is approximately 0.3 millimeters thick, protects the
egg against knocks and bumps. Directly behind this is the extremely thin
egg membrane, which is impermeable to bacteria, fungi and similar culprits.
Kimme looks up from his drawing: “Our task was to cut the shell while leaving the membrane completely intact.”
have spent decades using chicken eggs as sterile nutrient containers as part
of their efforts to grow viruses for attenuated vaccines, such as those used
against rabies, tetanus and malaria. But first you need to get the viruses
inside the egg: “Obviously the outer calcareous shell makes this extremely
tricky,” says Kimme. The standard approach has been to crack the shells
manually using mechanical pneumatic methods: “But no matter how careful you are handling the tool, the result tends to be pretty messy, with lots
of breakages and rejects,” says Kimme. “It really wasn’t very efficient—and
it obviously goes totally against the ethical treatment of living organisms,
because there are chicken embryos growing in the eggs.”
No more mess The job was commissioned by the Dessau Vaccine
Plant, now known as IDT Biologika. The pharmaceutical industry has long
been aware that eggs are the perfect choice for certain applications. They
A laser dance around the egg So Horst Kassner from the Dessau
Vaccine Plant decided to find a better way to open the shell. Hoping to hit
upon a sterile method, he asked LIM Laserinstitut Mittelsachsen GmbH
24
An IDT Biologika
employee watches the
shell separation process in
the cleanroom.
whether there was any way of doing it with lasers. LIM brought Kimme on
board as a mechanical engineer, and together they began experimenting.
“Calcium carbonate is an insulator like glass or plastic. So we quickly realized that a CO2 laser would be the best choice,” Kimme explains. “The laser
delivers light at a wavelength of between 9.4 and 10.6 micrometers, which is
absorbed very nicely by the calcareous eggshell.” The laser specialists carried
out several rounds of tests to optimize the parameters, ultimately creating a
stable industrial process that perfectly opens the eggshell in 99.9 percent of
cases. “The laser only cuts the shell. And the very low amount of heat that
is applied can be contained in the minimal coagulation at the beam entry
point.” Once the tests were completed, Kimme and his colleagues set about
building the special machine.
Laservorm GmbH
Opening on the fly The result was the Laser Egg Opener, or LEO. So
how does the process work in practice? First the fertilized eggs are placed in
a container that passes through an airlock. This prevents any surrounding
air from entering the processing chamber. At the interface between the two
zones, sensors detect whether the container is full, i.e. whether all spaces
contain an egg. This tells the laser if there are any unoccupied spaces that
it can safely ignore. The laser cutting process itself is carried out on the fly,
but without a scanner. “A scanner isn’t capable of scanning an entire rack
of eggs, so we came up with a faster method.” The egg container moves
through the laser system and the laser optics track its forward motion. The
laser beam is divided into four beams which are guided with millimeter
precision by mirrors. This establishes the optimum opening geometry for
the downstream process and means that the system always opens four eggs
at once. “It’s an extremely challenging process in terms of the control technology involved,” says Kimme. “But it allows us to process 3,000 eggs an
hour, which is ten times faster than using scanning optics.” The number of
eggs wasted is close to zero.
Once the eggs have been opened, a filter system sucks up any shell particles,
and the eggs continue their journey through a second airlock. This minimizes the risk of any bacteria hitching a ride. “Our customers work with
living organisms, and they are extremely sensitive to even the slightest nonconformity in the production process,” Kimme explains. “This is why it’s
crucial to have such tremendously high standards of hygiene—and this was
a huge challenge for us when it came to building the machine.” For example,
you can only use a limited number of very high alloy stainless steels and
certain plastics that are capable of withstanding the aggressive detergents
used in the industry. “We had to cut almost every screw thread ourselves.”
Other pharmaceutical companies are now also showing an interest in the
high-tech egg opener. “The market for this kind of application is tiny. But
thanks to laser technology, we can offer something truly unique.” Contact: Thomas Kimme, Phone: +49 3727 9974 – 0, [email protected]
25
Everything on a
larger scale: the
side wall of a
regional train at
Photon AG.
26
Angelika Grossmann
APPLICATION
The
automotive
industry has long
enjoyed the benefits of
lasers — and rail vehicle manufacturers are increasingly following suit.
Photon AG and its subsidiaries have been using
lasers successfully for years. Now they’re putting
them to the test in a prestigious large-scale project.
27
Photon AG is producing the outer shell of roughly 1,600 rail cars for the
ICE 4. Each side wall consists of five segments, each five meters long
(top). For Holger Alder (bottom left), this major order represents another
milestone in rail vehicle manufacturing. Photon AG manufactures rail car
side walls up to 25 meters long in its laser cabins (bottom right).
28
Angelika Grossmann
T
APPLICATION
en or fifteen years ago, the steel age seemed to be coming num to keep them as light as possible. “That’s a material that many people
to an end in the automotive industry as experts heralded associate with lightweight design, and rightly so,” says Alder. “But aluminum
a new era of aluminum. But then along came laser weld- generally has a lower tensile strength than steel. So to meet the load-bearing
ing, tailored blanks, 3D laser cutting, high-strength steels, huge requirements you have to compensate by using thicker materials and largeboosts in productivity, and the widespread emergence of light- volume profiles.” Since the width of trains is limited by the track gauge, this
weight steel construction. Applying these new developments increased volume could only be extended into the freight and passenger
to rail vehicle manufacturing is the recipe for success chosen compartments. The ICE 4 is aiming to regain this lost space for passengers
by Berlin-based Photon AG—and something of a personal mission for its by switching to an outer skin made of lightweight steel—obviously without
upping the weight or making any compromises in regard to rigidity or safety.
technical director, Holger Alder.
“In the auto industry, lasers have a proven track record of faster, cheaper Photon AG is familiar with these requirements from the automotive indusand more efficient performance. They’ve even created entirely new methods try and can fulfill them using laser technology. “To stay within the weight
of construction,” says Alder, who was employed by an automobile manu- limits, most of the outer steel shell can’t be any thicker than two millimeters.
facturer before joining Photon AG. “In the past few years, we’ve repeatedly Yet, if we were to weld metal that thin by conventional means, the amount
shown that the technologies used to build cars can also be applied to rail of heat applied would make the outer skin look like a rollercoaster track,”
vehicle manufacturing. But obviously this isn’t a one-to-one transfer—you Alder explains. “But thanks to the very high quality of laser weld seams, we
can weld even thin steels like this with virtually no distortion and virtually
need to get people on board and make them rethink what works best.”
no need for any postweld work.” Additional weight reductions are achieved
A prestigious large-scale project The know-how gained by Photon by using tailored blanks that ensure that all the sections of the outer skin are
AG in its early days suggests that this may be something of an understatement. only ever as thick as they need to be.
In fact, the differences between manufacturing automobiles and rail vehicles The side wall segments from Photon have already been fitted to seven
are substantial. While batch sizes in the auto industry often run into the hun- ICE 4 trains—some of which are already in on-track testing—and a furdreds of thousands, a decent order in the rail industry could be much small- ther four trains are currently in production. Once series production gets
er, perhaps in the region of several hundred parts. What’s more, the safety underway in late 2016, the company will be producing ten segments a day,
standards in rail vehicle manufacturing are sometimes higher than those in equivalent to the outer skin of one complete rail car. The logistics of dealing
the auto industry—especially when it comes to high-speed trains—and that with this quantity of components in such large dimensions is another chalmakes the processes involved more complex. Once a company has finally ob- lenge that Photon AG has mastered over the years. In fact, the company has
tained all the necessary stamps and certificates for a product, it can be tempt- manufactured almost 3,000 side walls for regional trains over the past three
ing to stick to the same track rather than reworking designs from scratch. years, some of which were as long as 16 meters. Five-meter sections seem
“Copy and paste is the lowest-risk method,” says Alder with a smile.
fairly easy to manage in comparison. “The big challenge of this project was
Yet at the same time the rail industry is facing similar problems to those to find a time-optimized automation method for producing the outer skin
besetting carmakers. For example, manufacturers are starting to pay more segments,” says Alder. Photon came up with the idea of producing the segattention to the weight of their rolling stock. Since many rail cars and loco- ments in two laser cabins that can be loaded from two sides. Each cabin conmotives have a service life of up to 30 years, every unnecessary kilogram will tains a robot that welds the sheet metal parts together and attaches them to
ultimately travel millions of kilometers, dragging down the train’s overall the longitudinal and transverse struts to keep them stable. While one autoenergy efficiency year after year. Efficiency is also becoming a bigger issue mated fixture is leaving the cabin with its welded assembly on board and the
on the production side as companies strive to make their rail vehicle manu- next is taking up position, a TruDisk disk laser is busy feeding the welding
facturing processes faster and more cost-effective. The challenges that make robot in the other cabin. This ensures optimum use of the laser at all times.
lasers an appealing option for rail vehicle manufacturers are practically the
same as those facing the automotive industry. Photon AG has overcome Aviation beckons Having already tackled both the automotive and
these challenges hundreds of times in recent years thanks to the advantages rail industries, Photon AG knows a thing or two about tapping into new
of laser machining. “Lasers enable us to save time, costs and materials in markets—and the company already has the next in its sights: “Our expericomponent welding while simultaneously boosting quality,” says Alder. The ence in designing and producing safety-relevant components and focusing
industry is increasingly embracing this approach. In 2014, Photon AG was on small and medium production runs makes us the perfect choice for jobs
awarded a prestigious large-scale project involving the production of side in the aviation industry. We’re hoping to secure more orders in that induswalls, roof panels and undercarriage components of around 1,600 rail cars try over the next few years.” The company is always careful to ensure that
for the new ICE 4, which Siemens/Bombardier is building for Deutsche customers get the competitive prices they expect. “Nobody buys things any
Bahn. Before assembling the prototype, Photon AG worked with the cus- more just because they have a ‘made by laser’ sticker on them! What customtomer to define the manufacturing strategy for the side walls. These are ers are ultimately looking for is high quality at a price that is comparable to
composed of five modules—each five meters long—which are almost com- that of conventional welding, or even lower.” pletely prefabricated by Photon AG before being assembled by Bombardier
in its own facility. In terms of materials, the ICE 4 marks a return to steel. Contact: Thomas Fittkau, Phone: +49 (0) 30 364088 – 0, [email protected]
The rail car bodies of previous incarnations of the ICE were made of alumi29
OPINION
James Bond …
AND LASER MATERIAL PROCESSING
007 finally succeeds in escaping certain death by luring the villain with his apparent insider knowledge.
The method used for the special effects suggest that Sean
Connery’s fear of the laser beam may have been more than just
good acting. The laser system was just a mock-up, with optical
trickery used to add the beam to the scene during editing. But
the cut in the table getting closer and closer to Connery’s torso was decidedly real. A member of the film crew was hidden
under the table using a welding torch to cut the table, which
had been prepared in advance, in half. A single slip-up could
have had dire consequences! The laser scene took on cult status because lasers were completely new at the time, heralding
a high-tech future. What’s more, director Guy Hamilton was
able to show what cutting metal with a laser would actually
look like—at least approximately.
What was visionary back then has become standard for us
today. What kinds of developments might the next 50 years
hold? What sorts of laser-based visions of the future will have
become a part of our everyday lives by then? Perhaps when
I’m 82 years old, I’ll be able to simply blink to project the answer into my field of vision using a miniature laser integrated in my bathrobe. What visions do you have for the future of laser applications ? Will they be part of our everyday lives in 50 years’ time ?
Send an email with your ideas to [email protected]
30
Gernot Walter
Laser Community’s
editor-in-chief
Athanassios Kaliudis
writes a regular
column on the laser
as an object of
popular culture.
When Theodore Maiman demonstrated the world’s first laser
in his laboratory in 1960, researchers were euphoric. Daring
visions of the future began to take shape in their heads. And
while engineers were still puzzling over the ins-and-outs and
looking for a problem for the laser to solve, Hollywood charged
ahead with an innovative idea: material processing. In the 1965
movie Goldfinger—probably one of the most successful and
defining examples of the 007 franchise—it wasn’t just James
Bond who burned himself into the collective consciousness of
a generation, but the laser, too.
Sean Connery — alias 007 — lies helpless, tied to a goldtopped table while master villain Goldfinger explains that he
no longer has any use for him. He therefore intends to kill him.
How? Using a futuristic tool called a laser. To help both 007
and moviegoers come to grips with the concept, the villain introduces the machine with the following words: “You are looking at an industrial laser, which emits an extraordinary light
not to be found in nature. It can project a spot on the moon
or, at closer range, cut through solid metal. I will show you.”
At this point a red laser beam begins slicing its way through
the table, threatening to cut Sean Connery in half. Goldfinger leaves Bond squirming, the face of the usually cool special
agent transformed with fear. A tense dialog ensues in which
Where’s
the
laser?
Reaching into eternity: The only data storage media that have proven
their ability to endure for thousands of years are stone and clay tablets.
Parchment and paper last a few hundred years under normal conditions,
CDs are expected to become unreadable after 50 years, and hard drives
have a lifespan of just ten years. Now researchers at Southampton University
are using femtosecond laser pulses to inscribe micrometer-scale binary
data on nano-structured quartz crystals the
size of a two-euro coin. The combination
of the size, orientation and position
of the nanostructures allows
information to be encoded in
five dimensions, yielding a
storage capacity of 380 terabytes.
The researchers say that the
data in the crystal can
remain intact for five billion
years. Who said nothing
Jastrow / Wikimedia Public Domain
lasts forever ?
© ETH-Bibliothek Zürich, Bildarchiv / Photographer: unknown / Hs_0304-1151-003 / Public Domain Mark
A hundred years
TO PROV E H E WA S R IGHT
In 1915, Albert Einstein presented his theory of general relativity, in which he hypothesized
the existence of gravitational waves, or ripples in spacetime. In 2015, scientists in Washington and
Louisiana detected these gravitational waves for the first time. Four 300 kilometer-long
laser beams distorted ever so slightly by tremors in the fabric of space and time caused by a collision
between two black holes 1.3 billion years ago. The signal lasted just a quarter of a second.
LASER COMMUNITY IS THE TRUMPF MAGAZINE FOR LASER USERS.
L E T ’ S M E E T O N L I N E : W W W. L A S E R - C O M M U N I T Y. C O M